Feed type for induced molting of commercial layer hens

An experiment employing three hundred and twenty 81-week-old Lohmann LSL commercial-breed hens was conducted to compare alternative induced-molting methods with the conventional method (fasting). Induced molting lasted 28 days at most, production and quality being monitored for four periods of 28 days thereafter. A completely randomized experimental design with five treatments, eight replicates of eight birds each per plot was adopted. The following experimental treatments were applied until a loss of 26% of body weight was reached: T1 - fasting, T2 - wheat bran ad libitum, T3 - rice bran ad libitum, T4 - cracked rice ad libitum, T5 - ground alfalfa ad libitum. Birds were then fed production diet ad libitum, except for those on treatment T1 (fasting) which received 30, 60 and 100 g/bird/day and then feed ad libitum. During induced molting the birds were exposed to a natural photoperiod and at day 28 that period was increased by 30 minutes/week until reaching 16 hours of light/day. The characteristics evaluated during induced molting were: feed intake, body weight changes and laying percentage. In the post-molt period, performance (feed intake, laying percentage, egg weight, egg mass, feed conversion ratio per dozen and per egg mass and percentage of broken eggs) and egg quality (specific gravity, eggshell breaking strength, percentages of eggshell, yolk, and albumen, eggshell thickness, yolk color and Haugh unit) were evaluated. Every 28 days one egg was collected from each repetition for three consecutive days for quality assessment. The use of rice bran and wheat bran is viable as molting inducers since the birds given those treatments display performance and egg quality similar to those fasted during the induced molting and also because these ingredients promote easier handling, eliminates the need for grinding and feed-mixing equipment and, being less aggressive, provide greater bird welfare.

Suplementação com gordura protegida para vacas de corte desmamadas precocemente mantidas em pastagem natural

The objective of this work was to evaluate the productive and reproductive performance of beef cows, as well as the performance of their calves according to the following dietary treatments: PRE: supplemented with protected fat (PF) during 45 days prepartum; PREPOS: supplemented with PF during 45 days prepartum and 63 days postpartum; POS: supplemented with PF during 63 days postpartum; PN: without supplementation. The productive performance of cows was not influenced by feed management (P>0.05), except for body condition score (BCS), which was lower for PRE and PREPOS cows at the end of mating season, with the latter cows having similar BCS POS and PN. The calving interval (CI) was shorter for cows supplemented in PREPOS - 376 days -, and did not differ in cows maintained in PN - 383 days. Supplemented PREPOS cows weaned 4.4% more pounds of calf per 100kg of cow at calving - 22.6kg - than the PRE and POS cows - 21.6kg and 21.6kg, respectively - and 8,4% more pounds of calf per 100 of cow at calving than the cows maintained in native pasture - 20.7kg. The fat protected supplementation during pre and/or postpartum periods did not affect the performance of cows and calves.

Natural history of an ant-plant-butterfly interaction in a Neotropical savanna

Non-myrmecophilous lepidopteran larvae using plants bearing ant attractants such as extrafloral nectaries are good models for studying morphological and behavioural mechanisms against ant predation. Udranomia spitzi (Hesperiidae) is a butterfly whose larvae feed on leaves of Ouratea spectabilis (Ochnaceae), a plant with extrafloral nectaries. We described the early stages of U. spitzi, and used field observations and experiments to investigate the defensive strategies of caterpillars against predatory ants. Larvae pass through five instars and pupation occurs inside larval leaf shelters. Ant-exclusion experiments revealed that the presence of ants did not affect significantly caterpillar survival. Predation experiments showed that vulnerability to ant predation decreased with increase in larval size. The present study showed that predatory ants are not as relevant as demonstrated for other systems, and also illustrates how observational data and field experiments can contribute to a better understanding of the biology and ecology of a species of interest.

Effect of rearing techniques and feed composition on productive traits, bird welfare and quality of poultry products

The PhD project was focused on the study of the poultry welfare conditions and improvements. The project work was divided into 3 main research activities. A) Field evaluation of chicken meat rearing conditions kept in intensive farms. Considering the lack of published reports concerning the overall Italian rearing conditions of broiler chickens, a survey was carried out to assess the welfare conditions of broiler reared in the most important poultry companies in Italy to verify if they are in accordance with the advices given in the European proposal COM (2005) 221 final. Chicken farm conditions, carcass lesions and meat quality were investigated. 1. The densities currently used in Italy are in accordance with the European proposal COM 221 final (2005) which suggests to keep broilers at a density lower than 30-32 kg live weight/m2 and to not exceed 38-40 kg live weight/m2. 2. The mortality rates in summer and winter agree with the mortality score calculated following the formula reported in the EU Proposal COM 221 final (2005). 3. The incidence of damaged carcasses was very low and did not seem related to the stocking density. 4. The FPD scores were generally above the maximum limit advised by the EU proposal COM 221 final (2005), although the stocking densities were lower than 30-32 kg live weight per m2. 5. It can be stated that the control of the environmental conditions, particularly litter quality, appears a key issue to control the onset of foot dermatitis. B) Manipulation of several farm parameters, such litter material and depth, stocking density and light regimen to improve the chicken welfare conditions, in winter season. 1. Even though 2 different stocking densities were established in this study, the performances achieved from the chickens were almost identical among groups. 2. The FCR was significantly better in Standard conditions contrarily to birds reared in Welfare conditions with lower stocking density, more litter material and with a light program of 16 hours light and 8 hours dark. 3. In our trial, in Standard groups we observed a higher content of moisture, nitrogen and ammonia released from the litter. Therefore it can be assumed that the environmental characteristics have been positively changed by the improvements of the rearing conditions adopted for Welfare groups. 4. In Welfare groups the exhausted litters of the pens were dryer and broilers showed a lower occurrence of FPD. 5. The prevalence of hock burn lesions, like FPD, is high with poor litter quality conditions. 6. The combined effect of a lower stocking density, a greater amount of litter material and a photoperiod similar to the natural one, have positively influenced the chickens welfare status, as a matter of fact the occurrence of FPD in Welfare groups was the lowest keeping the score under the European threshold of the proposal COM 221 final(2005). C) The purpose of the third research was to study the effect of high or low stocking density of broiler chickens, different types of litter and the adoption of short or long lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis during the hot season. 1. The feed efficiency was better for the Low Density than for High Density broilers. 2. The appearance of FPD was not influenced by stocking density. 3. The foot examination revealed that the lesions occurred more in birds maintained on chopped wheat straw than on wood shaving. 4. In conclusion, the adoptions of a short light regimen similar to that occurring in nature during summer reduces the feed intake without modify the growth rate thus improving the feed efficiency. Foot pad lesion were not affected neither by stocking densities nor by light regimens whereas wood shavings exerted a favourable effect in preserving foot pad in good condition. D) A study was carried out to investigate more widely the possible role of 25-hydroxycholecalciferol supplemented in the diet of a laying hen commercial strain (Lohmann brown) in comparison of diets supplemented with D3 or with D3 + 25- hydroxycholecalciferol. Egg traits during a productive cycle as well as the bone characteristics of the layers have been as well evaluated to determine if there the vitamin D3 may enhance the welfare status of the birds. 1. The weight of the egg and of its components is often greater in hens fed a diet enriched with 25-hydroxycholecalciferol. 2. Since eggs of treated groups are heavier and a larger amount of shell is needed, a direct effect on shell strength is observed. 3. At 30 and at 50 wk of age hens fed 25 hydroxycholecalciferol exhibited greater values of bone breaking force. 4. Radiographic density values obtained in the trial are always higher in hens fed with 25-hydroxycholecalciferol of both treatments: supplemented for the whole laying cycle (25D3) or from 40 weeks of age onward (D3+25D3).

Dimensionamiento del proceso de licuación de una planta de gas natural Offshore

Este proyecto consiste en el dimensionamiento del proceso de licuación de una planta offshore para la producción de gas natural licuado, usando únicamente N2 como refrigerante, evitando de este modo riesgos potenciales que podrían surgir con el uso de refrigerantes mixtos compuestos de hidrocarburos. El proceso ha sido diseñado para acomodar 35,23 kg/s (aproximadamente un millón de toneladas por año) de gas natural seco, sin separación de gases licuados de petróleo (GLP) y ajustarlo dentro de los parámetros requeridos en las especificaciones del proceso. Para proceder al dimensionamiento del proceso de licuación de gas natural de la planta se ha empleado el programa Aspen Plus. Los sistemas floating production, storage and offloading para licuar el gas natural (LNG-FPSO), es una nueva unidad conceptual y un modo realista y efectivo para la explotación, recuperación, almacenamiento, transporte y agotamiento de los campos marginales de gas y las fuentes de gas asociadas offshore. En el proyecto se detalla el proceso, equipos necesarios y costes estimados, potencia aproximada requerida y un breve análisis económico. ABSTRACT This project consist of the dimensioning of a liquefaction process in an offshore plant to produce liquefied natural, using only N2 as refrigerant in the cooling cycles to avoid potential hazards of mixed hydrocarbon refrigerants. The process was designed to accommodate 35.23 kg/s (roughly 1 MTPA) of raw natural gas feed without separation of LPG, and fits within all parameters required in the process specifications. The plant has been designed with the computer tool Aspen Plus. The floating production, storage and offloading system for liquefied natural gas (LNGFPSO), is a new conceptual unit and an effective and realistic way for exploitation, recovery, storage, transportation and end-use applications of marginal gas fields and offshore associated-gas resources. The following report details the process, equipment needs and estimated costs, approximated power requirements, and a brief economic analysis.

Marine isocyanides and related natural products structure, biosynthesis and ecology

This review highlights structural and biosynthetic work on a group of nitrogen-functionalised terpenes that are almost exclusively found in marine invertebrates and the animals that feed on them. The chemical functionality reviewed includes isocyanides, isothiocyanates, formamides, thiocyanates, isocyanates, and dichloroimines. The literature through mid 2003 is reviewed and there are 143 citations.

Transients and asymptotics of natural gradient learning

We analyse natural gradient learning in a two-layer feed-forward neural network using a statistical mechanics framework which is appropriate for large input dimension. We find significant improvement over standard gradient descent in both the transient and asymptotic phases of learning.

Evaluation of an alternative spectroscopic approach for aflatoxin analysis: Comparative analysis of food and feed samples with UPLC-MS/MS

Increasing research has highlighted the effects of changing climates on the occurrence and prevalence of toxigenic Aspergillus species producing aflatoxins. There is concern of the toxicological effects to human health and animal productivity following acute and chronic exposure that may affect the future ability to provide safe and sufficient food globally. Considerable research has focused on the detection of these toxins, based on the physicochemical and biochemical properties of the aflatoxin compounds, in agricultural products for human and animal consumption. As improvements in food security continue more regulations for acceptable levels of aflatoxins have arisen globally; the most stringent in Europe. These regulations are important for developing countries as aflatoxin occurrence is high significantly effecting international trade and the economy. In developed countries analytical approaches have become highly sophisticated, capable of attaining results with high precision and accuracy, suitable for regulatory laboratories. Regrettably, many countries that are affected by aflatoxin contamination do not have resources for high tech HPLC and MS instrumentation and require more affordable, yet robust equally accurate alternatives that may be used by producers, processors and traders in emerging economies. It is especially important that those companies wishing to exploit the opportunities offered by lucrative but highly regulated markets in the developed world, have access to analytical methods that will ensure that their exports meet their customers quality and safety requirements.

This work evaluates the ToxiMet system as an alternative approach to UPLC–MS/MS for the detection and determination of aflatoxins relative to current European regulatory standards. Four commodities: rice grain, maize cracked and flour, peanut paste and dried distillers grains were analysed for natural aflatoxin contamination. For B1 and total aflatoxins determination the qualitative correlation, above or below the regulatory limit, was good for all commodities with the exception of the dried distillers grain samples for B1 for which no calibration existed. For B1 the quantitative R² correlations were 0.92, 0.92, 0.88 (<250 μg/kg) and 0.7 for rice, maize, peanuts and dried distillers grain samples respectively whereas for total aflatoxins the quantitative correlation was 0.92, 0.94, 0.88 and 0.91. The ToxiMet system could be used as an alternative for aflatoxin analysis for current legislation but some consideration should be given to aflatoxin M1 regulatory levels for these commodities considering the high levels detected in this study especially for maize and peanuts

Study on the inhibitory effects of native medicinal plants on growth and aflatoxin production by toxigenic Aspergilli isolated from rainbow trout feed

In the present study, natural occurrence of fungi and aflatoxin B1 (AFB1) in pellet feed and feed ingredients used for rainbow trout was investigated with emphasis to Aspergillus section Flavi members and medicinal plants inhibitory to Aspergillus growth and/or AF production. The feed samples were cultured on the standard isolation media including dichloran rosebengal chloramphenicol agar (DRCA) and Aspergillus flavus/parasiticus agar (AFPA) for 2 weeks at 28 °C. Identification of fungal isolates was implemented based on the macro- and microscopic morphological criteria. AFs were detected using high performance liquid chromatography (HPLC). Based on the results obtained, a total of 109 fungal isolates were identified of which Aspergillus was the prominent genus (57.0%), followed by Penicillium (12.84%), Absidia (11.01%) and Pseudallscheria (10.10%). The most frequent Aspergillus species was A. flavus (60.66%) isolated from all the feed ingredients as well as pellet feed. Among 37 A. flavus isolates, 19 (51.35%) were able to produce AFB1 on yeast extract-sucrose (YES) broth in the range of 10.2 to 612.8 [tg/g fungal dry weight. HPLC analyses of trout feed showed that pellet feed and all feed ingredients tested except gluten were contaminated with different levels of AFB1 in the range of 1.83 to 67.35 lig/kg. In order to finding natural inhibitors of fungal growth and/or AF production, essential oils (EOs) and extracts of 49 medicinal plants were studied against an aflatoxin-producing A. parasiticus using a microbioassay technique. The EOs was analyzed by gas chromatography/mass spectrometry (GC/MS). Based on the results obtained, Achillea millefolium sub sp. elborsensis, Ferula gummosa, Mentha spicata, Azadirachta indica, Conium maculatum and Artemisia dracunculus remarkably inhibited A. parasiticus growth without affecting AF production by the fungus. Besides of Thymus vulgaris and Citrus aurantifolia, the EO of Foeniculum vulgare significantly inhibited both fungal growth (-70.0%) and AFs B1 and G1 (-99.0%) production. The EO of Carum carvi and ethyl acetate extract of Platycladus orientalis suppressed AFs B1 and G1 by more than 90.0%, without any obvious effect on fungal growth. The IC50 values of bioactive plants for AFs B1 and G1 were determined in the ranges of 90.6 to 576.2 and 2.8 to 61.9 µg/ml, respectively. Overall, results of the present study indicate the importance of AF contamination of trout feed as a risk factor for fish farming and thus, an urgent necessity for constant monitoring of trout feed for any unacceptable levels of AF contamination. Likewise, antifungal activities of bioactive plants introduced here would be an important contribution to explain the use of these plants as effective antimicrobial candidates to protect feeds from toxigenic fungus growth and subsequent AF contamination.

Non chemical natural organic matter removal with a contact TiO2 process

Dissertação de Mestrado, Tecnologia dos Alimentos, Instituto Superior de Engenharia, Universidade do Algarve, 2014

Characterization and evaluation of the impact of feed management on the effluents of Nile tilapia (Oreochromis niloticus) culture

O objetivo deste trabalho foi avaliar o efeito da utilização de diferentes manejos alimentares: alimento natural, ração peletizada, extrusada ou farelada, sobre a qualidade da água dos efluentes gerados em uma criação de tilápia do Nilo (Oreochromis niloticus). O experimento foi desenvolvido durante 19 semanas em doze viveiros de 300 m², com renovação contínua de água, povoados com juvenis machos de tilápia do Nilo na densidade de 1,7 peixes m-2. As rações isoproteícas (30% de proteína bruta) e isoenergéticas (3.000kcal de energia digestível) foram fornecidas duas vezes ao dia. Quanto ao tratamento alimento natural, foi utilizado esterco de galinha poedeira. Semanalmente, foram aferidos na água de abastecimento e nos efluentes, temperatura, oxigênio dissolvido, pH, fósforo total, nitrogênio total, clorofila a e material em suspensão. de maneira geral, houve piora na qualidade da água dos efluentes de todos os tratamentos estudados, em comparação a água de abastecimento, evidenciando o impacto ambiental desta atividade produtiva, podendo levar a eutrofização dos corpos d'água receptores.